Presently the only way a dentist can see a tooth surface below the level of the gingiva is to anesthetize the patent and surgically expose the area. Normally the dentist does not choose to surgically expose a subgingival area. Instead, he tries to find calculus and foreign objects on tooth surfaces by feeling the surface with a sharp explorer instrument.
Periodontal probes for measuring the depths of pockets or recesses which form between the tooth and the gum and for use in endodontic techniques involving measurements of root canals are known. A periodontal endoscope called the Perioscope has been reported in the literature. This device utilizes a 1.2 mm diameter coherent fiber optic endoscope with a wide angle lens at its tip. Also attached to the tip is a 5 mm long guide plate which is used to retract the anesthetized gingiva of the patient being examined. The image in the Perioscope is viewed by the dentist by putting his eye to the lens at the other end of the Perioscope. The Perioscope allows visualization of both the root and the epithelial wall of the pocket at a 4.times. magnification. The device is described in the following journal article:
Matsumoto K., Nakano K., Kojima T.: Direct Observation of the Root Wall and Pocket Tissue, Quintessence Int. 19:483, 1988.
However, the foregoing Perioscope can be difficult to use due to an inability to adjust the position of the lens relative to the Perioscope body as well as the light beam emanating from the fiber optic probe tip. Another difficulty with the Perioscope is that the gingiva must be anesthetized and reflected before the root can be fully visualized.